methods

var writable = concat(opts={}, cb)

Return a writable stream that will fire cb(data) with all of the data that
was written to the stream. Data can be written to writable as strings,
Buffers, arrays of byte integers, and Uint8Arrays.

By default concat-stream will give you back the same data type as the type of the first buffer written to the stream. Use opts.encoding to set what format data should be returned as, e.g. if you if you don't want to rely on the built-in type checking or for some other reason.

string - get a string

buffer - get back a Buffer

array - get an array of byte integers

uint8array, u8, uint8 - get back a Uint8Array

object, get back an array of Objects

If you don't specify an encoding, and the types can't be inferred (e.g. you write things that aren't in the list above), it will try to convert concat them into a Buffer.

If nothing is written to writable then data will be an empty array [].

error handling

concat-stream does not handle errors for you, so you must handle errors on whatever streams you pipe into concat-stream. This is a general rule when programming with node.js streams: always handle errors on each and every stream. Since concat-stream is not itself a stream it does not emit errors.